Dhātu (ayurveda)

Dhātus, n.pl. in Ayurveda, the seven fundamental principles that support the basic structure of the body.
They consist of:

Rasa dhatu the substratum formed just after the digestion of food. The main function of this Dhatu is nourishment.
Rakta dhatu This is the second Dhatu formed after the food digestion. This is formed from the former Dhatu, Rasa Dhatu
Mamsa dhatu This is the third Dhatu. This is formed from the former Dhatu, Rakta Dhatu. The main function of covering the bones.
Medus dhatu
Asthi dhatu
Majja dhatu
Shukra dhatu

Traditional texts often refer to these as the Seven Dhātus. Ojas, meaning vigour or vitality, is known as the eighth Dhātu, or Mahādhātu.